NAT personal summary

I. Introduction

The emergence of NAT is due to the depletion of global IP addresses.

Ii. Type

1. Intranet access

① Dynamic NAT

② Port multiplexing NAT

2. Intranet server ing

① One-to-one ing

② Port ing

3. TCP load balancing for Intranet servers

Iii. cisco Configuration

1. Intranet access

① Dynamic NAT

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R3:

Intranet gateway ip Address: 192.168.1.254

Internet ip Address: 12.1.1.1

　

Interfacef0/0

Ip address 192.168.1.254 255.255.255.0

No shutdown

Ip natinside

Interface f0/1

Ip address12.1.1.1255.20.255.0

No shutdown

Ip natoutside

Access-list 1 permit 192.168.1.0 0.0.255

Ip nat pool out2internet 12.1.1.10 12.1.1.20 netmask 255.255.255.0

Ip nat inside source list 1 pool out2internet [overload]

② Port multiplexing

Different from dynamic NAT, the nat address pool is defined as the same as the starting and ending ip addresses of a single ip address. The overload parameter must be added at the end of the nat global configuration:

Ip nat inside source list 1 pool out2internet overload

2. Intranet server ing

① One-to-one ip address ing

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Intranet Server ip Address: 192.168.1.1

Intranet gateway ip Address: 192.168.1.254

Ip address mapped to the Internet: 218.85.157.99

Interface f0/0

Ip address 192.168.1.254 255.255.255.0

No shutdown

Ip nat inside

Interface f0/1

Ip address 218.85.157.99 255.255.255.0

Ip nat outside

No shutdown

Ip nat inside source static 192.168.1.1 218.85.157.90

② Port ing. Here we use 80 web services as an example.

The IP address and interface configuration are consistent with the 1-to-1 ing.

Ip nat inside source tcp 192.168.1.1 80 218.85.157.90 80

3. TCP load balancing for Intranet servers

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1) interface f0/0
Ip nat inside

Ip address 192.168.1.254 255.255.255.0

No shutdown
Int f1/0
Ip nat outside

Ip address 218.85.157.90 255.255.255.0

No shutdown

2) access-list 1 permit host 218.85.157.90 // defines the public network ACL and only the IP address of the interface)

3) ip nat pool cisco 192.168.1.1 192.168.1.2 netmask 255.255.255.0 typerotary // defines the address pool of Intranet Server Load balancer.

4) ip nat inside destination list 1 pool cisco

This article is from the keepalive blog, please be sure to keep this source http://jefferyyu.blog.51cto.com/2843635/1300269